A compressor for forced air cooling of inner and outer rings of ball bearings

Abstract

The present invention relates to the field of compressors, and in particular to a compressor that provides forced air cooling for the inner and outer rings of ball bearings. The compressor comprises a casing, a front bearing seat, a rear bearing seat, a motor shaft, a ball bearing, an impeller, and a volute. The motor shaft is provided with a first channel, a second channel extending radially therethrough, and a third channel extending axially therethrough. The third channel is located on the outer wall of the motor shaft and passes through the inner side of the ball bearing inner ring. The casing is provided with a fourth channel, a fifth channel, and a seventh channel extending radially therethrough and communicating with the exterior. The first, second, third, and fourth channels are interconnected to form a heat dissipation channel for the inner ring. Fan blades for radial airflow are also fixedly mounted on the outer wall of the motor shaft and are located within the seventh channel. Both the front and rear bearing seats are provided with a sixth channel extending through the outer side of the ball bearing outer ring. The fifth, sixth, and seventh channels are interconnected to form a heat dissipation channel for the outer ring. This compressor improves the heat dissipation efficiency and service life of the ball bearings.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and in particular to a compressor for forced air cooling of inner and outer rings of ball bearings. Background Art

[0002] A gas compressor is a power device that converts mechanical energy into gas pressure energy. It is commonly used to provide gas power for pneumatic tools. It is also commonly used in industries such as petrochemicals, drilling, and metallurgy to pressurize and deliver media such as oxygen, hydrogen, ammonia, natural gas, coke oven gas, and inert gases.

[0003] A Chinese utility model patent application (publication number CN203906300U, publication date: 20141029) discloses a self-cooling dual-tank Roots blower, comprising a cylinder body, a left end cover and a right end cover provided on both sides of the cylinder body, a main oil tank provided on the left end cover, an auxiliary oil tank provided on the right end cover, a driving impeller shaft, and a driven impeller shaft; the driving impeller shaft and the driven impeller shaft are positioned by a gear pair provided in the main oil tank, and are supported by double-row ball bearings and cylindrical roller bearings; the driving impeller shaft and the driven impeller shaft are respectively provided with oil seals at the left end cover and at the right end cover, and an air pressure relief groove is provided between the air cavity in the cylinder body and the oil seal; the driving impeller shaft passes through the auxiliary oil tank, and the driving impeller shaft and the driven impeller shaft located in the auxiliary oil tank are respectively provided with an active oil slinger pan and a driven oil slinger pan. The utility model discloses a self-cooling double-oil-tank Roots blower with good heat dissipation performance, thereby increasing the service life of the blower.

[0004] The existing technology has the following shortcomings: the heat dissipation of traditional ball bearings uses the bearing chamber to dissipate heat for the outer ring of the bearing, and the heat dissipation of the inner ring of the bearing can only be mainly based on heat transfer; as a result, the heat dissipation effect of the ball bearing is not obvious, the working condition of the bearing is very poor, and the service life of the ball bearing in the compressor is greatly reduced. Summary of the Invention

[0005] The purpose of the present invention is: to address the above problems, it is proposed to set up an inner ring heat dissipation channel and an outer ring heat dissipation channel to dissipate heat for the inner ring and outer ring of the bearing respectively, thereby improving the heat dissipation effect of the ball bearing and increasing the service life of the ball bearing in the compressor. A compressor that forces air cooling on the inner and outer rings of the ball bearing.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] A compressor for forced air cooling of the inner and outer rings of a ball bearing, the compressor comprising a casing, a front bearing seat, a rear bearing seat, a motor shaft, a ball bearing, an impeller and a volute; the front bearing seat and the rear bearing seat are respectively fixed at the front and rear ends of the casing, a plurality of ball bearings are respectively sleeved on the outer wall of the motor shaft and located in the front bearing seat and the rear bearing seat, the impeller is fixed on the motor shaft and located in the compression channel of the volute; the motor shaft is provided with a first channel distributed axially and connected to the outside, a second channel penetrating radially and a third channel axially, the third channel is located on the outer wall of the motor shaft and passes through the inner side of the inner ring of the ball bearing; the casing is provided with a fourth channel, a fifth channel and a seventh channel penetrating radially and connected to the outside, the first channel, the second channel, the third channel and the fourth channel are connected to form an inner ring heat dissipation channel; fan blades for radial blowing are also fixedly provided on the outer wall of the motor shaft, the fan blades are located in the seventh channel; the front bearing seat and the rear bearing seat are both provided with a sixth channel, the sixth channel passes through the outer side of the outer ring of the ball bearing; the fifth channel, the sixth channel and the seventh channel are connected to form an outer ring heat dissipation channel.

[0008] Preferably, the front bearing seat and the rear bearing seat are both provided with ventilation rings, air inlet holes and ventilation grooves; the ventilation grooves pass through the outside of the outer ring of the ball bearing, the ventilation ring is connected to the fifth channel, and the ventilation grooves are connected to the ventilation ring through the air inlet holes to form a sixth channel.

[0009] Preferably, the front bearing seat and the rear bearing seat are further provided with a sealing ring groove, an O-ring is provided in the sealing ring groove, and multiple O-rings are radially located between the front bearing seat and the casing and between the rear bearing seat and the casing.

[0010] Preferably, the casing includes a motor barrel, a front end cover and a rear end cover; the front end cover and the rear end cover are respectively fixedly arranged at the front and rear ends of the motor barrel, and the front bearing seat and the rear bearing seat are respectively fixed on the front end cover and the rear end cover; multiple fourth channels and multiple fifth channels are respectively located on the front end cover and the rear end cover, and the seventh channel is located on the motor barrel.

[0011] Preferably, the front end cover and the rear end cover are both made of stainless steel.

[0012] Preferably, the impeller includes a first impeller and a second impeller, and the first impeller and the second impeller are respectively located at both ends of the motor shaft; the compressor is also provided with a fairing, and impeller positioning steps are respectively provided at both ends of the motor shaft, the outer wall of the motor shaft is provided with an external thread, and the fairing is provided with an internal thread; the inner side surfaces of the first impeller and the second impeller are respectively fitted with the outer side surfaces of the corresponding impeller positioning steps, and the two fairing internal threads are screwed together with the external threads of the motor shaft and respectively lock the first impeller and the second impeller to the motor shaft.

[0013] Preferably, the rotation directions of the two fairing internal threads are opposite and are the same as the rotation direction of the motor shaft.

[0014] Preferably, the first impeller and the second impeller are both closed impellers.

[0015] Preferably, the back of the impeller is provided with reinforcing ribs, the casing is provided with sealing grooves, and the outer circumferential surface of the reinforcing ribs and the sealing grooves form a labyrinth seal.

[0016] Preferably, the motor rotor is fixedly mounted on the outer wall of the motor shaft, and the motor stator is fixedly embedded in the inner wall of the casing; the motor rotor comprises a plurality of axially aligned and stacked silicon steel sheets, magnetic steels and carbon fiber sheaths, and the silicon steel sheets are provided with axially penetrating magnetic steel grooves; the magnetic steels are fixedly embedded in the magnetic steel grooves and correspond to the position of the motor stator, and the carbon fiber sheaths are fixedly sleeved on the outer wall of the silicon steel sheets, and the carbon fiber sheaths are used to prevent the internal silicon steel sheets and magnetic steels from being damaged.

[0017] The advantages of the compressor for forced air cooling of the inner and outer rings of ball bearings using the above technical solution of the present invention are:

[0018] During operation: 1) When the compressor is powered on, it drives the motor shaft to rotate, thereby driving the impeller and fan blades to rotate; 2) External air enters through the first channel and flows along the inner ring heat dissipation channel to dissipate heat from the inner ring of the ball bearing; 3) Simultaneously, driven by the fan blades, external air enters through the fifth channel and flows along the outer ring heat dissipation channel to dissipate heat from the outer ring of the ball bearing, completing the compressor's ball bearing cooling process. In this method, the cooling air in the inner ring heat dissipation channel passes through the inner ring of the ball bearing, and the cooling air in the outer ring heat dissipation channel passes through the outer ring of the ball bearing. In other words, both the inner and outer rings of the ball bearing are directly affected by the cooling air. This avoids the situation where the inner ring of the ball bearing can only dissipate heat through heat transfer and cannot dissipate heat directly, thereby improving the cooling effect and service life of the ball bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the inner circle heat dissipation channel and the outer circle heat dissipation channel.

[0021] Figure 3 This is a structural diagram of the motor shaft.

[0022] Figure 4 It is a cross-sectional view of the motor shaft in the AA direction.

[0023] Figure 5 、 Figure 6 Schematic diagram of the structure of the fan blade.

[0024] Figure 7 It is a structural diagram of the front bearing seat.

[0025] Figure 8 It is a cross-sectional view of the front bearing seat in the BB direction.

[0026] Figure 9 It is a structural diagram of the motor cylinder.

[0027] Figure 10 It is a cross-sectional view of the motor cylinder in the DD direction.

[0028] Figure 11 、 Figure 12 It is a structural diagram of the front end cover.

[0029] Figure 13 It is a cross-sectional view of the front end cover in the CC direction.

[0030] Figure 14 、 Figure 15 Schematic diagram of the impeller structure.

[0031] Figure 16 Schematic diagram of the structure of the fairing.

[0032] Figure 17 Schematic diagram of the compressor rotor structure. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Example 1

[0035] like Figure 1 、 Figure 2The compressor shown in the figure has forced air cooling for the inner and outer rings of the ball bearings, and the compressor includes a casing 1, a front bearing seat 2, a rear bearing seat 3, a motor shaft 4, a ball bearing 5, an impeller 6 and a volute 7; the front bearing seat 2 and the rear bearing seat 3 are respectively fixed to the front and rear ends of the casing 1, and a plurality of ball bearings 5 ​​are respectively sleeved on the outer wall of the motor shaft 4 and respectively located in the front bearing seat 2 and the rear bearing seat 3, and the impeller 6 is fixed on the motor shaft 4 and located in the compression channel of the volute 7; the motor shaft 4 is provided with a first channel 41 distributed axially and connected to the outside, a second channel 42 penetrating radially, and an axial third channel 43, and the third channel 43 is located on the motor shaft 4 outer wall and passes through the inner side of the inner ring of the ball bearing 5. The housing 1 is provided with a fourth channel 44, a fifth channel 45, and a seventh channel 47 that radially penetrate and communicate with the exterior. The first channel 41, the second channel 42, the third channel 43, and the fourth channel 44 are interconnected to form the inner ring heat dissipation channel. Fan blades 8 are also fixedly mounted on the outer wall of the motor shaft 4 for radial airflow, and are located within the seventh channel 47. Both the front bearing seat 2 and the rear bearing seat 3 are provided with a sixth channel 46 that passes through the outer side of the outer ring of the ball bearing 5. The fifth channel 45, the sixth channel 46, and the seventh channel 47 are interconnected to form the outer ring heat dissipation channel. During operation: 1) When the compressor is powered on, it drives the motor shaft 4 to rotate, thereby driving the impeller 6 and the fan blades 8 to rotate. 2) External air enters through the first channel 41 and flows along the inner ring heat dissipation channel to dissipate heat from the inner ring of the ball bearing 5. 3) Simultaneously, driven by the fan blades 8, external air enters through the fifth channel 45 and flows along the outer ring heat dissipation channel to dissipate heat from the outer ring of the ball bearing 5, completing the compressor's heat dissipation process for the ball bearing 5. In this manner, the cooling air in the inner ring heat dissipation channel passes through the inner ring of the ball bearing 5, and the cooling air in the outer ring heat dissipation channel passes through the outer ring of the ball bearing 5, that is, both the inner ring and the outer ring of the ball bearing 5 are directly affected by the cooling air; thereby avoiding the situation where the heat dissipation of the inner ring of the ball bearing 5 can only be mainly achieved by heat transfer and cannot be directly dissipated, thereby improving the heat dissipation effect and service life of the ball bearing 5.

[0036] like Figure 1 、 Figure 7 、 Figure 8 As shown, the front bearing seat 2 and the rear bearing seat 3 are both provided with a ventilation ring 21, an air inlet hole 22 and a ventilation groove 23; the ventilation groove 23 passes through the outer side of the outer ring of the ball bearing 5, the ventilation ring 21 is connected with the fifth channel 45, and the ventilation groove 23 is connected with the ventilation ring 21 through the air inlet hole 22 to form a sixth channel 46.

[0037] Both the front bearing seat 2 and the rear bearing seat 3 are further provided with sealing ring grooves 24, within which are disposed O-rings 25. Multiple O-rings 25 are radially located between the front bearing seat 2 and the casing 1, and between the rear bearing seat 3 and the casing 1. The O-rings provide effective damping for the front and rear bearing seats 2 and 3, reducing vibration of the compressor; they also prevent air from leaking from the outer ring heat dissipation channel to other locations in the compressor.

[0038] like Figure 1 As shown, the casing 1 includes a motor barrel 11, a front end cover 12 and a rear end cover 13; the front end cover 12 and the rear end cover 13 are respectively fixedly arranged at the front and rear ends of the motor barrel 11, and the front bearing seat 2 and the rear bearing seat 3 are respectively fixed on the front end cover 12 and the rear end cover 13; a plurality of fourth channels 44 and a plurality of fifth channels 45 are respectively located on the front end cover 12 and the rear end cover 13, and the seventh channel 47 is located on the motor barrel 11.

[0039] The front cover 12 and the rear cover 13 are both made of stainless steel. Stainless steel has a general thermal conductivity and forms a large temperature gradient between the back of the impeller 6 and the outer ring of the ball bearing 5, which is beneficial to the operation of the bearing.

[0040] The impeller 6 includes a first impeller 61 and a second impeller 62, which are located at both ends of the motor shaft 4. The compressor is also provided with a fairing 63. Impeller positioning steps are provided at both ends of the motor shaft 4. The outer wall of the motor shaft 4 is provided with an external thread, and the fairing 63 is provided with an internal thread. The inner surfaces of the first impeller 61 and the second impeller 62 respectively fit with the outer surfaces of the corresponding impeller positioning steps. The internal threads of the two fairings 63 are screwed together with the external threads of the motor shaft 4 to lock the first impeller 61 and the second impeller 62 to the motor shaft 4. The internal threads of the two fairings 63 rotate in opposite directions and both rotate in the same direction as the motor shaft 4. The first impeller 61 rotates clockwise as viewed from the inlet. To ensure that the fairing 63 rotates tighter and tighter, the internal threads of the front fairing 63 and the external threads on the outer wall of the front motor shaft 4 are both left-handed, and the front fan blades 8 should also rotate clockwise. The second impeller 62 rotates counterclockwise as viewed from the inlet. To ensure that the rear fairing 63 rotates tighter and tighter, the internal threads of the rear fairing 63 and the external threads on the outer wall of the rear motor shaft 4 are both right-handed, and the rear fan blades 8 should also rotate counterclockwise. The fairing 63 is also equipped with a collecting profile, through which external cooling air is introduced into the inner ring heat dissipation channel. The collecting profile ensures that air flows more efficiently into the motor shaft 4 while minimizing the impact on the compressor flow field efficiency.

[0041] The first impeller 61 and the second impeller 62 are both closed impellers.

[0042] like Figure 1 、 Figure 14 、 Figure 15As shown, impeller 6 is provided with reinforcing ribs 64 on its back to enhance its structural stability, minimizing deformation during high-speed rotation. The inner side of the ribs serves as a de-weighting surface for the impeller's dynamic balance. Casing 1 is provided with sealing grooves 65. The outer surface of the reinforcing ribs 64 and the sealing grooves 65 form a labyrinth seal to reduce leakage of high-temperature compressed gas and improve flow field efficiency.

[0043] like Figure 1 、 Figure 17 As shown, a motor rotor 91 is fixedly provided on the outer wall of the motor shaft 4, and a motor stator 92 is fixedly embedded on the inner wall of the casing 1; the motor rotor 91 includes a plurality of axially aligned and stacked silicon steel sheets 93, magnetic steels 94 and carbon fiber sheaths 95, and the silicon steel sheets 93 are provided with axially penetrating magnetic steel grooves 96; the magnetic steels 94 are fixedly embedded in the magnetic steel grooves 96 and correspond to the position of the motor stator 92, and the carbon fiber sheaths 95 are fixedly sleeved on the outer wall of the silicon steel sheets 93, and the carbon fiber sheaths 95 are used to prevent the internal silicon steel sheets 93 and magnetic steels 94 from being damaged.

Claims

1. A compressor for forced air cooling of the inner and outer rings of ball bearings, characterized in that: The compressor comprises a casing (1), a front bearing seat (2), a rear bearing seat (3), a motor shaft (4), a ball bearing (5), an impeller (6) and a volute (7); the front bearing seat (2) and the rear bearing seat (3) are respectively fixed to the front and rear ends of the casing (1); a plurality of ball bearings (5) are respectively sleeved on the outer wall of the motor shaft (4) and are respectively located in the front bearing seat (2) and the rear bearing seat (3); the impeller (6) is fixed on the motor shaft (4) and is located in the compression channel of the volute (7); the motor shaft (4) is provided with a first channel (41) distributed axially and communicating with the outside, a second channel (42) penetrating radially, and a third channel (43) extending axially; the third channel (43) is located on the outer wall of the motor shaft (4) and passes through the ball bearing seat. The inner side of the inner ring of the bearing (5); the housing (1) is provided with a fourth channel (44), a fifth channel (45) and a seventh channel (47) which penetrate radially and communicate with the outside, and the first channel (41), the second channel (42), the third channel (43) and the fourth channel (44) are connected to form an inner ring heat dissipation channel; the outer wall of the motor shaft (4) is also fixedly provided with a fan blade (8) for radial blasting, and the fan blade (8) is located in the seventh channel (47); the front bearing seat (2) and the rear bearing seat (3) are both provided with a sixth channel (46), and the sixth channel (46) passes through the outer side of the outer ring of the ball bearing (5); the fifth channel (45), the sixth channel (46) and the seventh channel (47) are connected to form an outer ring heat dissipation channel.

2. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The front bearing seat (2) and the rear bearing seat (3) are both provided with a ventilation ring (21), an air inlet hole (22) and a ventilation slot (23); the ventilation slot (23) passes through the outer side of the outer ring of the ball bearing (5), the ventilation ring (21) is connected to the fifth channel (45), and the ventilation slot (23) is connected to the ventilation ring (21) through the air inlet hole (22) to form a sixth channel (46).

3. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The front bearing seat (2) and the rear bearing seat (3) are both provided with a sealing ring groove (24), an O-type sealing ring (25) is provided in the sealing ring groove (24), and a plurality of O-type sealing rings (25) are respectively located radially between the front bearing seat (2) and the housing (1) and between the rear bearing seat (3) and the housing (1).

4. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The housing (1) includes a motor barrel (11), a front end cover (12), and a rear end cover (13); the front end cover (12) and the rear end cover (13) are fixedly arranged at the front and rear ends of the motor barrel (11), respectively; the front bearing seat (2) and the rear bearing seat (3) are fixed on the front end cover (12) and the rear end cover (13), respectively; the plurality of fourth channels (44) and the plurality of fifth channels (45) are respectively located on the front end cover (12) and the rear end cover (13), and the seventh channel (47) is located on the motor barrel (11).

5. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 4, characterized in that: The materials of the front end cover (12) and the rear end cover (13) are both stainless steel.

6. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The impeller (6) includes a first impeller (61) and a second impeller (62), and the first impeller (61) and the second impeller (62) are respectively located at both ends of the motor shaft (4); the compressor is further provided with a fairing (63), and both ends of the motor shaft (4) are respectively provided with impeller positioning steps, the outer wall of the motor shaft (4) is provided with an external thread, and the fairing (63) is provided with an internal thread; the inner side surfaces of the first impeller (61) and the second impeller (62) are respectively fitted with the outer side surfaces of the corresponding impeller positioning steps, and the two internal threads of the fairing (63) are screwed together with the external thread of the motor shaft (4) to lock the first impeller (61) and the second impeller (62) to the motor shaft (4).

7. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 6, characterized in that: The internal threads of the two fairings (63) have opposite rotation directions and both rotate in the same direction as the motor shaft (4).

8. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: Both the first impeller (61) and the second impeller (62) are closed impellers.

9. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The back of the impeller (6) is provided with a reinforcing rib (64), the casing (1) is provided with a sealing groove (65), and the outer cylindrical surface of the reinforcing rib (64) and the sealing groove (65) form a labyrinth seal.

10. A compressor for forced air cooling of inner and outer rings of ball bearings according to claim 1, characterized in that: The motor rotor (91) is fixedly provided on the outer wall of the motor shaft (4), and the motor stator (92) is fixedly embedded in the inner wall of the housing (1); the motor rotor (91) comprises a plurality of silicon steel sheets (93), magnetic steels (94) and carbon fiber sheaths (95) that are axially aligned and stacked, and the silicon steel sheets (93) are provided with magnetic steel grooves (96) that pass through in the axial direction; the magnetic steels (94) are fixedly embedded in the magnetic steel grooves (96) and correspond to the positions of the motor stator (92); the carbon fiber sheaths (95) are fixedly sleeved on the outer wall of the silicon steel sheets (93), and the carbon fiber sheaths (95) are used to prevent the silicon steel sheets (93) and magnetic steels (94) inside from being damaged.

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