A W-type combined sealing ring structure for radial braking of an electric spindle

Abstract

The present application relates to a W-shaped combined seal ring structure for radial braking of an electric spindle, which relates to the field of hydraulic cylinders. The structure comprises a seal ring body, wherein a pressure groove for communicating with a hydraulic oil chamber is provided in the middle of the peripheral wall of the seal ring body. When the seal ring body is in use, the pressure groove is sac-shaped, and the inner wall of the pressure groove is provided with a pressure equalizing groove, and two pressure equalizing grooves are symmetrically provided along the center cross-section of the thickness of the seal ring body. The provision of the pressure equalizing grooves in the present application enables the seal ring body to deform uniformly when subjected to force, achieving a good sealing effect while braking and clamping the active shaft.

Description

Technical Field

[0001] The present application relates to the field of hydraulic cylinders, and in particular to a W-shaped combined sealing ring structure for radial braking of an electric spindle. Background Art

[0002] A common brake cylinder assembly consists of a brake cylinder body and a brake friction ring. The brake cylinder body has a mounting cavity connected to the oil chamber. The mounting cavity ring is located outside the brake friction ring. A pressure ring is installed in the mounting cavity, and the inner wall of the pressure ring abuts the brake friction ring. During use, the oil chamber applies pressure to the deformable ring inside the mounting cavity, causing the pressure ring to deform and move closer to the brake friction ring, causing the brake friction ring to deform and move closer to the rotating shaft, thereby clamping the rotating shaft and achieving the braking effect.

[0003] Currently, the pressure ring uses a rubber ring. When the rubber ring structure deforms under low pressure, the hydraulic oil pressure cannot maintain sufficient pressure on the outer lip of the rubber ring to adhere tightly to the contact surface of the brake cylinder. As a result, hydraulic oil leaks through the gaps on both sides, causing the electric spindle to malfunction. Furthermore, rubber has poor wear resistance. After long-term use, repeated friction with the contact surface of the brake cylinder will cause wear and tear, resulting in oil leakage. This can cause oil contamination inside the electric spindle, contaminating the internal structure and the encoder. Summary of the Invention

[0004] In order to improve the problem that the pressure ring is prone to oil leakage at low pressure and affects the use of the electric spindle, the present application provides an electric spindle radial brake W-type combined sealing ring structure.

[0005] The present application provides a W-shaped combined seal ring structure for radial braking of an electric spindle, which adopts the following technical solutions:

[0006] A W-shaped combined sealing ring structure for radial braking of an electric spindle includes a sealing ring body, a pressure groove for communicating with a hydraulic oil chamber is provided in the middle of the peripheral wall of the sealing ring body, the pressure groove is sac-shaped when the sealing ring body is in use, and a pressure equalizing groove is provided on the inner wall of the pressure groove, and two pressure equalizing grooves are symmetrically arranged along the center section of the thickness of the sealing ring body.

[0007] By adopting the above technical solution, after the staff installs the sealing ring body in the installation cavity of the brake cylinder body, during use, the hydraulic oil chamber applies pressure to the sealing ring body, and the pressure is transmitted to both sides of the sealing ring body through the sac-shaped pressure groove, and then transmitted to the pressure equalizing groove. The pressure equalizing groove absorbs the pressure and releases it evenly to the inner wall of the sealing ring body. The sealing ring body as a whole undergoes uniform deformation, so that the sealing ring body and the inner wall of the installation cavity always maintain a sealed state and continuously tighten the brake friction ring, so that the friction ring can evenly tighten the rotating shaft to achieve the braking effect.

[0008] Optionally, the pressure groove separates the sealing ring body into two corners, and the corner is inclined from the side close to the pressure groove toward the side wall of the sealing ring body, and the side of the corner close to the pressure groove is higher than the side of the corner away from the pressure groove.

[0009] By adopting the above technical solution, after the sealing ring body is installed, the end with high edges and corners abuts against the installation cavity more tightly. When the pressure groove in the middle of the sealing ring body is subjected to force, the pressure is transmitted from the pressure groove to the sealing ring body, causing the edges and corners on both sides of the sealing ring body to deform. The end with low edges and corners is thinner and deforms toward the inner wall of the installation cavity under force. After the end with low edges and corners abuts against the installation cavity and receives force, the pressure is dispersed to both sides, thereby making the end with high edges and corners abut against the installation cavity more tightly, thereby preventing hydraulic oil from leaking therefrom.

[0010] Optionally, special-shaped annular grooves are provided on both sides of the sealing ring body, and the special-shaped annular grooves include a vertical surface and an annular inclined surface, the vertical surface is parallel to the cross section of the sealing ring body on the thickness, and the vertical surface is arranged close to the inner annular surface of the sealing ring body.

[0011] By adopting the above technical solution, the opening of the special-shaped ring groove reduces the thickness of the sealing friction ring body close to the friction ring. When the sealing membrane ring body is subjected to low pressure, the part close to the friction ring can be better uniformly deformed to achieve a clamping braking effect. The annular bevel is the angular side wall. The annular bevel is set so that when the sealing ring body is installed, if the annular bevel needs to be pressed against the inner wall of the installation cavity, the part with high edges and corners will inevitably move toward the center of the pressure groove, thereby causing the pressure groove to deform into a cystic structure, thereby achieving uniform deformation of the sealing ring body and avoiding leakage of hydraulic oil.

[0012] Optionally, a mounting cavity is provided on the vertical surface, and a sealing ring is clamped in the mounting cavity.

[0013] By adopting the above technical solution, the installation cavity and the pressure groove are located on the same horizontal line on the cross-section of the sealing ring body. That is, the installation cavity and the pressure groove divide the sealing ring body into an upper half containing the sharp corners and a lower half adjacent to the friction ring. When pressure is applied to the oil chamber, the pressure is mainly transmitted through the pressure groove and concentrated on the sharp corners. The two sides of the sharp corners deform and tightly abut against the inner wall of the installation cavity, preventing oil leakage. The pressure evenly released by the pressure equalizing groove causes the lower half to deform evenly, evenly holding the friction ring to achieve braking. After the sealing ring body is installed, the sealing ring always maintains abutment against the inner wall of the installation cavity. When the sealing ring body is deformed by force, the oil chamber pressure is transmitted to the sealing ring, causing the sealing ring to deform and abut more tightly against the inner wall of the installation cavity, further preventing oil leakage.

[0014] Optionally, the sealing ring body is made of polyurethane.

[0015] By adopting the above technical solution, the polyurethane material is more wear-resistant and the service life of the sealing ring body is extended.

[0016] Optionally, the sealing ring is made of rubber.

[0017] By adopting the above technical solution, the rubber material is harder than the polyurethane material. When the sealing ring body is subjected to low pressure, the deformation of the sealing ring is smaller than the deformation of the sealing ring body, so that the sealing ring always maintains a tight contact with the inner wall of the installation cavity, thereby improving the anti-oil leakage effect of the sealing ring body under low pressure conditions.

[0018] In summary, the present application includes at least one of the following beneficial technical effects of the W-type combined seal ring structure for radial braking of an electric spindle:

[0019] 1. After the staff installs the sealing ring body in the brake cylinder, the pressure groove is sac-shaped. During use, the pressure of the sealing ring body is evenly released through the pressure groove and the pressure equalizing groove. The sealing ring body deforms evenly. While the friction ring evenly holds the rotating shaft to achieve braking, both sides of the sealing ring body always maintain contact with the inner wall of the installation cavity to prevent oil leakage.

[0020] 2. Under low pressure conditions, the deformation of the sealing ring body is mainly caused by the sharp corners on both sides of the pressure groove. After the sharp corners are deformed, they are in closer contact with the inner wall of the installation cavity to avoid oil leakage.

[0021] 3. Since the sealing ring material is harder than the sealing ring body, the sealing ring deforms slightly after receiving the force transmitted by the sealing ring body, and can always maintain a closer fit with the inner wall of the installation cavity, further preventing oil leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0023] Figure 2 It is a schematic diagram of the overall cross-sectional structure of an embodiment of the present application;

[0024] Figure 3 It is a schematic diagram of the overall structure of the embodiment of the present application in use state.

[0025] Figure numerals: 1. Sealing ring body; 2. Pressure groove; 3. Pressure equalizing groove; 4. Edge; 5. Special-shaped ring groove; 6. Installation cavity; 7. Sealing ring; 8. Hydraulic oil cavity; 9. Installation cavity. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-3 This application is described in further detail.

[0027] The present application discloses a W-type combined sealing ring structure for radial braking of an electric spindle. Figure 1 and Figure 2 , including a sealing ring body 1, the sealing ring body 1 is made of polyurethane, and a pressure groove 2 for communicating with the hydraulic oil chamber 8 is arranged in the middle of the peripheral wall of the sealing ring body 1. The pressure groove 2 is rectangular and the corners are chamfered. The pressure groove 2 evenly disperses the pressure applied by the hydraulic oil chamber 8. The inner wall of the pressure groove 2 is provided with a pressure equalizing groove 3. There are two pressure equalizing grooves 3 symmetrically arranged along the thickness center section of the sealing ring body 1, and the corners of the pressure equalizing grooves 3 are all chamfered.

[0028] refer to Figure 2 The pressure groove 2 separates the sealing ring body 1 into two corners 4. The corners 4 are inclined from the side close to the pressure groove 2 toward the side wall of the sealing ring body 1, and the side of the corners 4 close to the pressure groove 2 is higher than the side of the corners 4 away from the pressure groove 2. Special-shaped ring grooves 5 are provided on both sides of the sealing ring body 1. The special-shaped ring grooves 5 include a vertical surface and an annular inclined surface. The vertical surface is parallel to the cross section of the sealing ring body 1 along the thickness, and the vertical surface is close to the inner ring surface of the sealing ring body 1 and is connected to the inner ring wall surface of the sealing ring body 1. The annular inclined surface is inclined outward from the inside of the sealing ring body 1 and is connected to the lower side of the corners 4. That is, on the vertical cross section of the sealing ring body 1, the distance between the outermost end point of the corner 4 and the center line of the pressure groove 2 is greater than the distance between the vertical surface of the special-shaped ring groove 5 and the center line of the pressure groove 2.

[0029] Since the processing of the sac-shaped groove in the prior art is relatively difficult, in this embodiment, a special-shaped ring groove 5 is provided. During installation, in order to make the inclined surface of the corner 4 away from the pressure groove 2 abut against the inner wall of the installation cavity 9, the thickness of the sealing ring body 1 used is greater than the width of the installation cavity 9. After the vertical surfaces on both sides of the special-shaped ring groove 5 are tightly abutted against the installation cavity 9, the inclined surface on the outside of the corner 4 is deformed toward the pressure groove 2, thereby making the pressure groove 2 form a sac shape that can evenly release pressure, and after the inclined surface is completely abutted against the inner wall of the installation cavity 9, the high end of the corner 4 is tightly abutted against the inner wall of the installation cavity 9. When the pressure groove 2 releases pressure toward the corner 4, the vertical surface and the annular inclined surface of the special-shaped ring groove 5 always remain tightly abutted against the inner wall of the installation cavity 9 to avoid oil leakage.

[0030] At the same time, on the vertical cross-section of the sealing ring body 1, the special-shaped annular groove 5 is opposite to the side wall of the pressure equalizing groove 3, so that under the low pressure condition of the hydraulic oil chamber 8, when the pressure equalizing groove 3 releases pressure evenly to the bottom, the lower half of the sealing ring body 1 can still be deformed evenly, thereby improving the holding braking effect.

[0031] refer to Figure 3The corners 4 on both sides of the pressure groove 2 are arranged with the special-shaped ring groove 5, so that after the pressure groove 2 forms a sac-like structure, the ends with high corners 4 abut against the inner wall of the installation cavity 9, and there is a certain deformation space between the ends with low corners 4 and the installation cavity 9. When the pressure of the hydraulic oil chamber 8 is transmitted to the corners 4 through the pressure groove 2, the ends with low corners 4 deform and move toward the inner wall of the installation cavity 9 to abut, so that the ends with high corners 4 abut against the inner wall of the installation cavity 9 more tightly, further preventing leakage of hydraulic oil.

[0032] refer to Figure 2 and Figure 3 In order to further improve the anti-leakage performance of the sealing ring body 1, installation cavities 9 are opened on the vertical surfaces of the special-shaped ring groove 5 on both sides of the sealing ring body 1. In order to facilitate processing and production, the installation cavity 9 is set as a rectangular groove, and a sealing ring 7 is clamped in the installation cavity 9. The sealing ring 7 uses an existing rubber O-ring, that is, the cross-section of the sealing ring 7 is circular, and the diameter of the sealing ring 7 is larger than the depth of the installation cavity 9. Since the installation cavity 9 is opposite to the pressure equalizing groove 3, that is, the two installation cavities 9 and the two pressure equalizing grooves 3 reduce the thickness of the part below the pressure groove 2 of the sealing ring body 1, when the oil chamber pressure is low, the main pressure of the sealing ring body 1 is dispersed to the part of the corner 4 through the pressure groove 2. The part below the pressure groove 2 is uniformly deformed under the action of the pressure equalizing groove 3 to evenly hold the friction ring.

[0033] Since the sealing ring 7 is made of a rubber material that is harder than polyurethane, after the sealing ring body 1 is installed, the sealing ring 7 is pressed against the inner wall of the installation cavity 9. Under low pressure, the sealing ring body 1 is deformed by force, and the sealing ring 7 always remains pressed against the installation cavity 9, further preventing leakage of hydraulic oil.

[0034] The implementation principle of the W-type combined sealing ring structure of the electric spindle radial brake in the embodiment of the present application is: after the sealing ring main body 1 is installed, the sealing ring 7 is pressed against the inner wall of the installation cavity 9, the sealing ring main body 1 is deformed, and the pressure groove 2 in the middle is a semi-capsule structure. The sharp corners 4 on both sides of the pressure groove 2, the ends with high sharp corners 4 abut against the inner wall of the installation cavity 9, and there is a deformation space between the ends with low sharp corners 4 and the installation cavity 9. When the pressure of the hydraulic oil chamber 8 is evenly transmitted to the sealing ring 7 main body through the pressure equalizing groove 3, the sealing ring main body 1 is evenly deformed to hold the rotating shaft, and the ends with low sharp corners 4 are deformed and move toward the inner wall of the installation cavity 9 to abut, so that the ends with high sharp corners 4 abut against the inner wall of the installation cavity 9 more tightly to avoid leakage of hydraulic oil. The sealing ring 7 is always pressed against the installation cavity 9 to further prevent oil leakage.

[0035] The above-mentioned electric spindle radial brake W-type combined seal ring structure is used in fatigue test experiment. The experimental method is as follows:

[0036] Experimental equipment: A205WS electric spindle (Renishaw encoder), hydraulic station.

[0037] Experimental steps:

[0038] 1. The W-type combined sealing ring structure with radial brake of electric spindle is marked as brake cylinder No. 1, and the brake cylinder with rubber ring structure commonly used in the market is marked as brake cylinder No. 2. Braking test is carried out with brake cylinder No. 1 and brake cylinder No. 2 respectively. The spindle is set to rotate at high speed of 1000 rpm for 10 seconds, and it is stopped at 0 rpm for 5 seconds. Then the servo control hydraulic station is started to increase the brake pressure from 0 to 5MPA and maintain it for 10 seconds. The spindle is operated at low speed of 100 rpm for 5 seconds and repeated. The cumulative number of pressure tests is not less than 100,000 times.

[0039] Because Renishaw encoders require very high environmental cleanliness, leaking oil from the W-ring can splash onto the rotating spindle encoder surface, causing the encoder to trigger an alarm. During the experiment, the brake cylinder was removed every 5-8 days to observe whether there was any oil leakage.

[0040] 2. Connect the brake cylinder body interface equipped with the electric spindle radial brake W-type combined sealing ring structure and the common rubber ring structure on the market in step 1 to compressed air and place it in a container filled with water. Make sure it is completely immersed below the water surface with an air pressure of 0.8 MPa. Observe whether there is any bubble leakage.

[0041] Experimental results: No bubbles were generated in brake cylinder No. 1; a small amount of bubbles were generated in brake cylinder No. 2. The present application discloses a W-shaped combined seal ring structure for radial braking of an electric spindle with good wear resistance and anti-leakage performance.

[0042] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A W-type combined sealing ring structure for radial braking of an electric spindle, characterized by: The invention comprises a sealing ring body (1), wherein a pressure groove (2) for communicating with a hydraulic oil chamber (8) is provided in the middle of a peripheral wall of the sealing ring body (1), wherein the pressure groove (2) is in a sac shape when the sealing ring body (1) is in use, and a pressure equalizing groove (3) is provided in the inner wall of the pressure groove (2), and two pressure equalizing grooves (3) are symmetrically provided along the center cross section of the thickness of the sealing ring body (1); The pressure groove (2) separates the sealing ring body (1) into two corners (4), and the corners (4) are arranged to be inclined from the side close to the pressure groove (2) toward the side wall of the sealing ring body (1), and the side of the corner (4) close to the pressure groove (2) is higher than the side of the corner (4) away from the pressure groove (2); Both sides of the sealing ring body (1) are provided with special-shaped annular grooves (5), the special-shaped annular grooves (5) comprising a vertical surface and an annular inclined surface, the vertical surface being parallel to the cross section of the sealing ring body (1) in thickness, and the vertical surface being arranged close to the inner annular surface of the sealing ring body (1); An installation cavity (6) is provided on the vertical surface, and a sealing ring (7) is clamped in the installation cavity (6).

2. The W-shaped combined sealing ring structure for radial braking of an electric spindle according to claim 1, characterized in that: The sealing ring body (1) is made of polyurethane.

3. The W-shaped combined sealing ring structure for radial braking of an electric spindle according to claim 2, characterized in that: The sealing ring (7) is made of rubber.

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