CN104021720A - Epicyclic gear train experiment training aid - Google Patents

Abstract

The present invention provides an experimental teaching aid for an epicyclic gear train, which is characterized in that it comprises: an epicyclic gear train; an input unit; and a data acquisition and display unit, wherein the epicyclic gear train has a large sun gear, a first small sun gear, a second small sun gear wheel, the third small sun wheel, the first planetary wheel, the second planetary wheel, the third planetary wheel and the planet carrier; and the third small sun wheel and the big sun wheel are connected through the first sliding mechanism, the first planetary wheel and the second planetary wheel The two planetary gears are connected through the second sliding mechanism. The movement of the two sliding mechanisms can drive the relevant gears, and the meshing state of the gears in the epicyclic gear train will change, so that the epicyclic gear train is in a negative sign mechanism and two positive sign mechanisms. switch between institutions. The epicyclic train experimental teaching aid of the present invention can demonstrate the switching of the sign mechanism of the epicyclic train and verify the calculation formula of the transmission ratio.

Description

Experimental teaching aid for epicyclic gear train

technical field

The invention relates to an experimental teaching aid for an epicyclic wheel train, which belongs to the field of teaching tools.

Background technique

In the teaching of mechanical design principles, the epicyclic gear train is an important and difficult teaching content.

The transmission ratio of the epicyclic gear train cannot be directly calculated. It is necessary to use the principle of relative motion to transform the epicyclic gear train into an imaginary fixed-axis gear train, and then use the formula for calculating the gear ratio of the fixed-axis gear train to calculate the transmission ratio of the epicyclic gear train. The imaginary fixed-axis gear train obtained through conversion is called a conversion mechanism or a conversion gear train. If the transmission ratio of an epicyclic gear train conversion mechanism is positive, then the epicyclic gear train is a positive sign mechanism; otherwise, it is a negative sign mechanism. The sign of the transmission ratio of the conversion mechanism can be judged by (-1)m, where m is the number of times the gears are meshed. That is to say, when the number of times of external meshing of the gears in the epicyclic train is odd, the epicyclic train is a negative mechanism; when the number of external meshes of the gears is even, the epicyclic mechanism is a positive mechanism.

Taking the 2K-H type epicyclic gear train with two center wheels and one planet carrier as an example, the transmission ratio formula of this epicyclic gear train is: i ₁₃ ^H =(n ₁ -n _H )/(n ₃ -n _H ) =(-1) ¹ Z ₃ /Z ₁ ;

Converted to (n ₁ /n _H -1)/(n ₃ /n _H -1) = (-1) ¹ Z ₃ /Z ₁ ;

Let X=n ₁ /n _H , Y=n ₃ /n _H ;

This gives (X-1)/(Y-1)=-Z ₃ /Z ₁ .

Among them, n ₁ is the speed of one center wheel, n ₃ is the speed of the other center wheel, n _H is the speed of the planet carrier, Z ₁ is the speed of one center wheel, and Z ₃ is the speed of the other center wheel.

Connect the numerical plots of X=n ₁ /n _H and Y=n ₃ /n _H , and if a straight line with a slope of -Z ₃ /Z ₁ and passing through the point (1, 1) is obtained, the epicyclic wheel can be verified The establishment of the formula for calculating the transmission ratio of the train.

The teaching content of the epicyclic wheel train plus and minus sign mechanism and the calculation formula of the transmission ratio is very abstract, and it is difficult for students to fully understand it only by relying on the teacher's oral expression. Moreover, there is still no intuitive teaching tool that can demonstrate the transmission ratio formula and verify the transmission ratio calculation formula in the current teaching.

Contents of the invention

The present invention is made in order to solve the above-mentioned problems, and the purpose is to provide an epicyclic train experimental teaching tool for demonstrating the switching of the sign mechanism of the epicyclic train and verifying the calculation formula of the transmission ratio.

The present invention adopts the following structures in order to achieve the above object.

The present invention provides an experimental teaching aid for an epicyclic train, which is characterized in that it comprises: an epicyclic train; an input unit; and a data acquisition and display unit,

Among them, the epicyclic gear train includes: sun gear, planet gear and planet carrier,

The center gear includes the large sun gear with Z ₁ teeth, the first small sun gear with Z ₂ teeth, the second small sun gear with Z ₃ teeth, and the third small sun gear with Z ₄ teeth; the planetary gear includes Z ₅ teeth The first planetary gear, the second planetary gear with the number of teeth Z ₆ , and the third planetary gear with the number of teeth Z ₇ ; Z ₁ , Z ₂ , Z ₃ , Z ₄ , Z ₅ , Z ₆ and Z ₇ satisfy the following relationship: Z ₁ = 2Z ₅ +Z ₂ ; Z ₄ +Z ₇ =Z ₃ +Z ₆ =Z ₅ +Z ₂ ,

The large sun gear is an internal gear with a gear cover on the right side, which is vacantly sleeved on the main shaft; the first small sun gear and the second small sun gear are fixedly connected to the main shaft from right to left; the third small sun gear is located on the second small sun gear The left side of the wheel is empty on the main shaft, and the third small sun gear and the big sun gear are connected through the first sliding mechanism.

The first planetary gear can be internally meshed with the large sun gear and externally meshed with the first small sun gear; the first planetary gear and the second planetary gear are connected through the second sliding mechanism, and are keyed on the epicyclic shaft from right to left; The three planetary wheels are located on the left side of the second planetary wheel and are fixedly connected to the epicyclic shaft;

There is at least one planetary carrier fixedly connected between the main shaft and the epicyclic shaft. One end of the planetary carrier is vacantly sleeved on the main shaft through a bearing, and the other end is fixedly connected to the epicyclic shaft.

When the big sun gear, the first small sun gear and the first planetary gear are in the meshing state, the epicyclic gear train is a minus sign mechanism; when the first sliding mechanism moves to the right, the big sun gear and the third small sun gear are right shift, so that the large sun gear is out of mesh with the first planetary gear, the third small sun gear is in the meshed state with the third planetary gear, the first small sun gear and the first planetary gear are kept in meshed state, and the epicyclic gear train is transformed into the first type Positive sign mechanism; when the second sliding mechanism moves to the left, the first planetary wheel and the second planetary wheel move leftward as a whole, so that the first small sun wheel and the first planetary wheel are disengaged, and the second small sun wheel and the second The planetary gears enter the meshing state, the third small sun gear and the third planetary wheel maintain the meshing state, and the epicyclic gear train transforms into the second positive sign mechanism,

The input unit includes: the spindle speed input device connected with the main shaft; the large sun gear speed input device connected with the gear cover,

The data acquisition and display unit includes: the spindle speed acquisition device connected with the main shaft; the planet carrier speed acquisition device connected with the planet carrier; the large sun gear speed acquisition device connected with the big sun gear; The rotation speed acquisition device, the first display, the second display and the third display connected to the large sun gear rotation speed acquisition device are used to display the rotation speed.

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the first sliding mechanism includes: a first bushing fixedly connected to the third small sun gear; The second bushing on the gear cover and empty on the main shaft, the second bushing is provided with a groove; the third bushing embedded in the groove of the second bushing, the third bushing and the second bushing The pipe can be rotated relatively, and is connected with the first handle of the first casing and the third casing, and a guide rail is arranged under the first handle.

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the second sliding mechanism includes: a fourth sleeve connected between the first planetary wheel and the second planetary wheel, and the fourth The sleeve is keyed on the epicyclic shaft, and the second handle connected with the fourth sleeve.

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the main shaft rotational speed input device is the first handwheel connected with the main shaft, through which the main shaft can be shaken; the large sun gear rotational speed input The device includes: a first pulley fixedly connected to the second sleeve, a second pulley located in front of the first pulley with the same parameters as the first pulley, a transmission belt connected to the first pulley and the second pulley, and the second pulley The second pulley is connected with the second handwheel, and the second handwheel shakes, and the rotating speed can be transmitted to the big sun wheel through the first pulley, the transmission belt, the second pulley and the second bushing in sequence.

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the main shaft speed input device is a continuously variable speed motor connected with the main shaft, and the large sun gear speed input device is connected to the second bushing motor.

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the spindle speed acquisition device is a first magnetic sensor connected to the first display through a wire, and the first magnetic sensor is close to the spindle to measure Spindle speed; planet carrier speed acquisition device includes: the second magnetic sensor connected to the second display through wires, the fifth bushing fixedly connected to the planet carrier, the first bushing empty on the fifth bushing, the fifth bushing The second magnetic sensor is close to the fifth casing to measure the rotation speed of the planet carrier; the large sun gear speed acquisition device includes: the third magnetic sensor connected to the third display through a wire, and the third magnetic sensor is close to the second casing to measure the large Sun gear speed;

In addition, in the epicyclic gear train experimental teaching aid of the present invention, it may also have such a feature: wherein, the data acquisition and display unit further includes: a first bevel gear fixedly connected to the fifth sleeve; and the first bevel gear has the same The second bevel gear of the parameter, the first bevel gear and the second bevel gear are in meshing state; the first bevel gear shaft connected between the first bevel gear and the second bevel gear; the first bevel gear shaft connected at the end of the first bevel gear shaft One pointer, the third bevel gear fixed on the main shaft; the fourth bevel gear with the same parameters as the third bevel gear, the third bevel gear and the fourth bevel gear are in meshing state; the third bevel gear and the fourth bevel gear are connected The second bevel gear shaft between the gears; the first spur gear connected to the second bevel gear shaft; the second spur gear with the same parameters as the first spur gear, the first spur gear and the second spur gear are in meshing state ; The sixth bushing that is connected to the second spur gear, and the sixth bushing is sleeved on the first bevel gear shaft; the second pointer that is connected to the end of the sixth bushing.

In addition, in the epicyclic gear train experiment teaching aid of the present invention, it may also have such a feature: wherein, the planet carrier is a flange.

Invention function and effect

According to the epicyclic gear train experimental teaching aid of the present invention, because the epicyclic gear train has a large sun gear, a first small sun gear, a second small sun gear, a third small sun gear, a first planetary gear, a second planetary gear, and a third planetary gear and the third small sun gear and the big sun gear are connected through the first sliding mechanism, and the first planetary gear and the second planetary gear are connected through the second sliding mechanism, so the movement of the two sliding mechanisms can drive The relevant gears make the meshing state of the gears in the epicyclic gear train change, so that it can demonstrate that the epicyclic gear train switches between a negative sign mechanism and two positive sign mechanisms.

In addition, since the epicyclic gear train experimental teaching aid of the present invention also has an input unit and a data acquisition and display unit, it can input variable rotational speeds for the large sun gear and the main shaft, and simultaneously output the rotational speeds of the large sun gear, the main shaft and the planetary carrier, while the rotational speed of the main shaft The rotational speed is the same as that of the first small sun gear, so a set of data can be obtained with the rotational speed ratio X of the first small sun gear and the planet carrier, and the rotational speed ratio of the large sun gear and the planet carrier as Y, with X and Y as the coordinate values By drawing a graph, it can be verified that the two have a linear relationship, and the slope is -Z ₁ /Z ₂ , and pass through the point (1, 1), so that the formula for calculating the transmission ratio of the epicyclic gear train can be verified.

Description of drawings

Fig. 1 is the schematic diagram of the structure of the epicyclic train experimental teaching aid when the epicyclic train is a negative sign mechanism in Embodiment 1 and Embodiment 2;

Fig. 2 is a schematic structural view of the epicyclic train experimental teaching aid in Embodiment 1 and Embodiment 2 when the epicyclic train is the first positive sign mechanism;

Fig. 3 is a schematic structural view of the epicyclic train experimental teaching aid in Embodiment 1 and Embodiment 2 when the epicyclic train is the second positive sign mechanism; and

Fig. 4 is a plot diagram of the rotational speed ratio of the gear and the planetary carrier in the embodiment 2 of the epicyclic train experimental teaching aid involved in the present invention.

Detailed ways

The epicyclic gear train experimental teaching aid involved in the present invention will be described in detail below with reference to the accompanying drawings.

<Example 1>

Fig. 1 is a schematic structural view of the epicyclic train experimental teaching aid in Embodiment 1 and Embodiment 2 when the epicyclic train is a minus sign mechanism.

Fig. 2 is a schematic structural view of the epicyclic train experimental teaching aid in Embodiment 1 and Embodiment 2 when the epicyclic train is the first positive sign mechanism.

FIG. 3 is a schematic structural view of the epicyclic train experimental teaching aid in Embodiment 1 and Embodiment 2 when the epicyclic train is the second positive sign mechanism.

As shown in FIG. 1 , FIG. 2 and FIG. 3 , the epicyclic train experimental teaching aid 50 has an epicyclic train, an input unit, and a data collection and display unit.

Epicyclic gear train comprises: large sun gear 1, first small sun gear 22, second small sun gear 20, third small sun gear 7, first planetary gear 2, second planetary gear 3, third planetary gear 6, and The second flange 5.

The input unit includes: a first handwheel 10 , a first pulley 30 , a transmission belt 26 , a second pulley 25 , and a second handwheel 27 .

The data acquisition and display unit includes: a first magnetic sensor (not shown in the figure), a second magnetic sensor (not shown in the figure), a third magnetic sensor (not shown in the figure), a first display (not shown in the figure) ), the second display (not shown in the figure), the third display (not shown in the figure), the first bevel gear 8, the first bevel gear shaft 35, the second bevel gear 17, the first pointer 36, the third bevel gear 9. The second bevel gear shaft 34 , the fourth bevel gear 11 , the first spur gear 13 , the second spur gear 15 , the second pointer 37 , and the dial 38 .

The main shaft 21 traverses the entire box body 33 from the middle, and the two ends are fixed on the left and right sides of the box body 33 . The first hand wheel 10 is located outside the left side of the box body 33 and is fixedly connected to the main shaft 21 . The first hand wheel 10 is shaken to input the rotational speed for the main shaft 21 .

The large sun gear 1 is an internal gear with 135 teeth, and the right side has a gear cover 39 , and the gear cover 39 is vacantly sleeved on the main shaft 21 . The first small sun gear 22 with 25 teeth and the second small sun gear 20 with 32 teeth are fixedly connected on the main shaft 21 from right to left.

The third small sun gear 7 and the big sun gear 1 are connected through the first sliding mechanism. The right side of the gear cover 39 of the sun gear 1 is empty on the main shaft 21; the second sleeve 32 is provided with a groove, and the third sleeve 29 is embedded in the groove of the second sleeve 32; the third sleeve 29 and the second sleeve 32 can rotate relatively; the first handle 46 is located below the main shaft 21, and connects the first sleeve 19 and the third sleeve 29; a guide rail (not shown) is provided under the first handle 46, and the guide rail is fixed on Box body 33 bottoms; The third handle 45 is connected to the right end of the first handle 46, and stretches out the box body 33 from the right side; The third handle 45 moves to the right, can drive the first handle 46 to move right, and the first handle 46 drives the first cover again The pipe 19 and the third casing 29 move to the right as a whole, and the third casing 29 drives the second casing 32 to move to the right at the same time.

The first planetary gear 2 with 55 teeth is located inside the large sun gear 1 . The number of teeth of the second planetary gear 3 is 48. The first planetary wheel 2 and the second planetary wheel 3 are connected through the second sliding mechanism, and the specific structure is: the fourth sleeve 4 is connected between the first planetary wheel 2 and the second planetary wheel 3, and is keyed to the epicyclic shaft 40; the second handle 23 is a rectangle, the upper left corner is fixed on the fourth sleeve 4, and the middle part of the right end is connected to the seventh sleeve 24; the eighth sleeve 31 with a groove is set empty on the second sleeve 32 , and is located on the left side of the third sleeve 29; the seventh sleeve 24 is embedded in the groove of the eighth sleeve 31, the seventh sleeve 24 and the eighth sleeve 31 can rotate relatively; the middle part of the left end of the fourth handle 28 is connected On the eighth sleeve 31, the middle passes through the box body 33, and the right end extends out of the box body 33; the fourth handle 28 moves to the left, and can drive the eighth sleeve 31, the seventh sleeve 24 and the second handle in turn 23 moves to the left, and the second handle 23 drives the first planetary wheel 2, the fourth sleeve pipe 4 and the second planetary wheel 3 to move leftward as a whole.

The first flange (not shown in the figure) and the second flange 5 are the planet carrier of the epicyclic gear train. The lower end of the first flange is vacantly sleeved on the main shaft 21 through a bearing, and is located between the first small sun gear 22 and the gear cover 39 . The upper end of the first flange is fixedly connected to the epicyclic shaft 40 and is located on the right side of the first planetary wheel 2 . The lower end of the second flange 5 is vacantly sleeved on the main shaft 21 through a bearing, and is located on the left of the second small sun gear 20 . The upper end of the second flange 5 is fixedly connected to the epicyclic shaft 40 and is located to the left of the fourth sleeve 4 . The first flange and the second flange 5 are connected together by a connecting rod 44 .

The third planetary gear 6 with 45 teeth is fixed on the rightmost end of the epicyclic shaft 40 and is located on the left of the upper part of the second flange 5 . The left end of the bottom of the second flange 5 is fixedly connected with the fifth sleeve 41, and the first sleeve 19 is sleeved above the fifth sleeve 41, and the number of teeth fixed on the first sleeve 19 is 35, which is the third small sun gear 7.

When the big sun gear 1, the first small sun gear 22 and the first planetary gear 2 are in the meshing state, the number of external meshes of the gears in the epicyclic gear train is 1, and the epicyclic gear train is a negative sign mechanism, and the epicyclic gear train experimental teaching aid 50 is in the state of The state shown in Figure 1.

The third handle 45 moves to the right, which can drive the first handle 46 to move, and the first handle 46 drives the first sleeve pipe 19 and the third sleeve pipe 29 to move as a whole, and the third sleeve pipe 29 drives the second sleeve pipe 32 to move to the right simultaneously, so that The large sun gear 1 is disengaged from the first planetary gear 2 , the third small sun gear 7 is engaged with the third planetary gear 6 , and the first small sun gear 22 is kept in a meshed state with the first planetary gear 2 . At this time, the number of external meshes of the gears in the epicyclic gear train is 2, and the epicyclic gear train is transformed into the first positive sign mechanism, and the epicyclic gear train experimental teaching aid 50 is in the state shown in FIG. 2 .

The fourth handle 28 moves to the left, which can drive the eighth sleeve pipe 31, the seventh sleeve pipe 24 and the second handle 23 to move to the left in turn, and the second handle 23 drives the first planetary wheel 2, the fourth sleeve pipe 4 and the second The second planetary gear 3 moves to the left as a whole, so that the first small sun gear 22 and the first planetary gear 2 are disengaged, the second small sun gear 20 and the second planetary gear 3 enter the meshing state, and the third small sun gear 7 and the third planetary gear Wheel 6 remains engaged. At this time, the number of external meshes of the gears in the epicyclic gear train is 2, and the epicyclic gear train is transformed into the second positive sign mechanism, and the epicyclic gear train experimental teaching aid 50 is in the state shown in FIG. 3 .

The first pulley 30 is fixedly connected to the second sleeve 32 and located between the third sleeve 29 and the eighth sleeve 31 . The second pulley 25 is fixed on the inner wall of the front end of the box body 33 and is connected with the first pulley 30 through the transmission belt 26 . The second hand wheel 27 is located outside the right side of the casing 33 and is fixedly connected to the second pulley 25 . The second hand wheel 27 shakes, and the rotational speed can be transmitted to the large sun gear 1 through the second pulley 25 , the transmission belt 26 , the first pulley 30 and the second sleeve 32 in sequence.

The first magnetic sensor is fixed on the box body 33, measures the rotational speed of the main shaft 21 by being close to the main shaft 21, and is connected with the first display through a wire, and the first display can display the integer part of the main shaft 21 rotational speed. The second magnetic sensor is also fixed on the casing 33, measures the rotating speed of the second flange 5 by approaching the fifth bushing 41, and is connected with the second display by a wire, and the second display can display the second flange 5 Integer part of rotational speed. The third magnetic sensor is fixed on the box body 33, measures the rotational speed of the main shaft 21 by approaching the second bushing 32, and is connected with the third display through a wire, and the third display can display the integer part of the rotational speed of the large sun gear 1.

The first bevel gear 8 is fixedly connected to the fifth sleeve 41 and is located on the left side of the first sleeve 19 . The second bevel gear 17 has the same parameters as the first bevel gear 8, and the first bevel gear 8 and the second bevel gear 17 are in meshing state. The first bevel gear shaft 35 is connected between the first bevel gear 8 and the second bevel gear 17 , and the first bearing 16 is sleeved therebetween. The first bearing 16 is fixed on the first bearing seat 43 , and the first bearing seat 43 is fixed on the bottom of the box body 33 . The end of the first bevel gear shaft 35 is connected with the first pointer 36 . There is a dial 38 behind the first pointer 36, and the dial 38 has a scale, which is fixed on the outside of the front of the casing 33. The reading of the first pointer 36 is the fractional part of the rotational speed of the second flange 5 .

The third bevel gear 9 is fixed on the leftmost end of the main shaft 21 and is located inside the box body 33 . The fourth bevel gear 11 has the same parameters as the third bevel gear 9, and the third bevel gear 9 and the fourth bevel gear 11 are in meshing state. The second bevel gear shaft 34 is connected between the third bevel gear 9 and the fourth bevel gear 11 , and the second bearing 12 is sleeved therebetween. The second bearing 12 is fixed on the second bearing seat 42 , and the second bearing seat 42 is fixed on the bottom of the box body 33 . The end of the second bevel gear shaft 34 is connected with the first spur gear 13 . The second spur gear 15 has the same parameters as the first spur gear 13, and the first spur gear 13 and the second spur gear 15 are in meshing state. The rear of the second spur gear 15 is connected with the sixth bushing 14 , and the sixth bushing 14 is sleeved on the first bevel gear shaft 35 . The end of the sixth sleeve 14 is connected with the second pointer 37 . Both the second pointer 37 and the first pointer 36 are located in front of the dial 38 . The reading of the second pointer 37 is the fractional part of the rotation speed of the main shaft 21 .

Function and effect of embodiment

According to the experimental teaching aid of the epicyclic gear train involved in this embodiment, because the epicyclic gear train has a large sun gear, a first small sun gear, a second small sun gear, a third small sun gear, a first planetary gear, a second planetary gear, The third planetary gear and the planet carrier; and the third small sun gear and the large sun gear are connected through the first sliding mechanism, and the first planetary gear and the second planetary gear are connected through the second sliding mechanism, so the two sliding mechanisms The movement can drive the relevant gears, so that the meshing state of the gears in the epicyclic gear train can be changed, so that it can demonstrate that the epicyclic gear train switches between a negative sign mechanism and two positive sign mechanisms.

<Example 2>

When the large sun gear 1, the first small sun gear 22 and the first planetary gear 2 are in the meshing state in the epicyclic gear train experimental teaching aid 50 in Embodiment 1, the epicyclic gear train is a negative sign mechanism, and it is a 2k-H type epicyclic gear train, the formula for calculating the transmission ratio of the epicyclic gear train should be: i ₁₂₂ ^H =(n ₂₂ -n _H )/(n ₁ -n _H )=(-1) ¹ Z ₁ /Z ₂ ;

Converted to (n ₂₂ /n _H -1)/(n ₁ /n _H -1) = (-1) ¹ Z ₁ /Z ₂ ;

Let X=n ₂₂ /n _H , Y=n ₁ /n _H ;

This gives (X-1)/(Y-1)=-Z ₁ /Z ₂ .

Wherein, n ₂₂ is the rotational speed of the first small sun gear 22, n ₁ is the rotational speed of the large sun gear 1, and n _H is the rotational speed of the second flange 5; then X is the first small sun gear 22 and the second flange The rotation speed ratio of the disk 5, Y is the rotation speed ratio between the large sun gear 1 and the second flange 5. Z ₁ is 135 teeth of the large sun gear 1, Z ₂ is 25 teeth of the first small sun gear 22, -Z ₁ /Z ₂ =-135/25.

When the first handwheel 10 shakes, it can input the rotating speed for the main shaft 21; while the first small sun wheel 22 is fixedly connected on the main shaft 21, which is the same as the rotating speed of the main shaft 21, and the first hand wheel 10 can also input the rotating speed for the first small sun wheel 22. Rotating speed. When the second hand wheel 27 is shaken, the rotation speed can be transmitted to the large sun gear 1 through the second pulley 25 , the transmission belt 26 , the first pulley 30 and the second sleeve 32 in sequence.

The first display can output the integer part of the rotational speed of the main shaft 21, that is, the integer part of the rotational speed n ₂₂ of the first small sun gear 22; the second pointer 37 can display the fractional part of the rotational speed of the main shaft 21, that is, display the first small sun gear 22 Fractional part of speed n ₂₂ . When the rotational speed of the first handwheel 10 changes, the reading changes of the first display and the second pointer 37 are recorded in Table 1.

The third display can output the integer part of the rotational speed n1 of the large sun gear _1. When the rotational speed of the second handwheel 27 changes, the reading changes of the third display are recorded in Table 1.

The second display can output the integer part of the rotating speed n _H of the second flange 5, and the first pointer 36 can display the fractional part of the rotating speed n _H of the second flange 5, and the reading changes of the second display and the first pointer 36 are recorded in in FIG. 1.

Table 1 Speed data record table

Integer part of n ₂₂ +101 +103 -101 -100 0 +101 fractional part of n ₂₂ 10/12 10/12 3.5/12 9.5/12 0 3/12 integer part of n ₁ +69 -71 +71 -76 +70 0 Integer part of n _H +73 -38 +50 -78 +58 +16 fractional part of n _H 9.5/12 7/12 4.5/12 5/12 5/12 10/12

Wherein, the value method of the positive and negative signs in Table 1 is as follows: looking from left to right, it is stipulated that the clockwise rotation direction is "+", and the counterclockwise rotation direction is "-".

Calculate the values of n ₂₂ , n ₁ , X=n ₂₂ /n _H , Y=n ₁ /n _H and list them in Table 2

Table 2 Numerical Table of Speed Ratio of Gear and Planetary Carrier

n ₂₂ +101.8 +103.8 -101.3 -100.08 0 +101.3 n ₁ +69 -71 +71 -76 +70 0 _f +73.8 -38.6 -50.4 -78.4 +58.4 +16.8 x 0.93 1.84 1.4 0.96 1.2 0 Y 1.38 -2.69 -2.01 1.29 0 6.01

Use the mathematical calculation software matlab to connect the numerical plot points of X=n ₂₂ /n _H and Y=n ₁ /n _H , and get a straight line as shown in Figure 4 after fitting. It can be seen from Figure 4 that there is a linear relationship between the two. The slope of the fitting curve is -5, approximately equal to -5.4, which is approximately equal to -135/25; and passing through the point (0.96, 1.29), it is similar to a straight line passing through the point (1, 1), so the calculation of the transmission ratio of the epicyclic gear train The formula can be verified to hold true.

When the epicyclic wheel system teaching aid 50 is a negative sign mechanism, the experimental students shake the first handwheel 10 to feel the magnitude of the rotational torque of the first handwheel 10. The third handle 45 moves to the right, and the epicyclic gear train is converted into the first positive sign mechanism. The experimental students shake the first handwheel 10 to feel the change in the rotational torque of the first handwheel 10 . The fourth handle 28 moves to the left, and the epicyclic wheel train is converted into the second positive sign mechanism. The experimental students shake the first handwheel 10 to feel the change in the rotational torque of the first handwheel 10 .

Function and effect of embodiment

According to the epicyclic gear train experimental teaching aid involved in this embodiment, since it has an input unit and a data acquisition and display unit, it can input variable rotational speeds for the large sun gear and the main shaft, and simultaneously output the rotational speeds of the large sun gear, the main shaft and the planet carrier, and The rotational speed of the main shaft is the same as that of the first small sun gear, so a set of data can be obtained with the rotational speed ratio X of the first small sun gear and the planetary carrier, and the rotational speed ratio of the large sun gear and the planetary carrier as Y, with X and Y as Drawing a graph of the coordinate values can verify that the two have a linear relationship, and the slope is -Z ₁ /Z ₂ , and pass through the point (1, 1), so that the formula for calculating the transmission ratio of the epicyclic gear train can be verified.

In addition, according to the experimental teaching aids of the epicyclic gear train involved in this embodiment, when the epicyclic gear train is a positive mechanism, the experimental students can obviously feel a large resistance when shaking the first hand wheel, and the rotational torque of the first hand wheel is relatively large compared to the epicyclic gear train. When it is a negative mechanism, it increases a lot, which can explain that the transmission efficiency of the epicyclic gear train of the positive mechanism is much worse than that of the negative mechanism, so it can be verified that the transmission efficiency of the positive mechanism is much smaller than that of the negative mechanism.

Of course, the experimental teaching aid for epicyclic trains involved in the present invention is not limited to the structures in the above embodiments.

Claims (8)

1. a cyclic train experiment teaching aid, is characterized in that, comprising:

Cyclic train;

Input block; And

Data acquisition display unit,

Wherein, described cyclic train comprises: centre wheel, planetary gear and planet carrier,

Described centre wheel comprises that the number of teeth is Z ₁large sun gear, the number of teeth be Z ₂the first small sun gear, the number of teeth are Z ₃the second small sun gear, the number of teeth are Z ₄the 3rd small sun gear; Described planetary gear comprises that the number of teeth is Z ₅the first row star-wheel, the number of teeth be Z ₆the second planetary gear, the number of teeth be Z ₇the third line star-wheel; Described Z ₁, Z ₂, Z ₃, Z ₄, Z ₅, Z ₆and Z ₇meet following relation: Z ₁=2Z ₅+ Z ₂; Z ₄+ Z ₇=Z ₃+ Z ₆=Z ₅+ Z ₂,

Described large sun gear is annular wheel, and right side has gear cap, and empty set is on main shaft; Described the first small sun gear and described the second small sun gear right-to-left are connected on described main shaft; Described the 3rd small sun gear is positioned at described the second small sun gear left, and empty set is on described main shaft, and described the 3rd small sun gear is connected by the first slipping mechanism with described large sun gear,

Described the first row star-wheel can with described large sun gear in mesh, with described the first small sun gear external toothing; Described the first row star-wheel is connected by the second slipping mechanism with described the second planetary gear, and right-to-left is connected in all rotating shafts; Described third planet wheel is positioned at described the second planetary gear left, is connected in described all rotating shafts;

Between described main shaft and described all rotating shafts, be fixedly connected with planet carrier described at least one, one end of described planet carrier is by bearing empty set on described main shaft, and the other end is connected in described all rotating shafts,

When described large sun gear, described the first small sun gear and described the first row star-wheel are during in engagement, described cyclic train is negative mechanisms; When described the first slipping mechanism moves right, described large sun gear and described the 3rd small sun gear integral body move to right, described large sun gear and described the first row star-wheel drop out of gear are closed, described the 3rd small sun gear and described the third line star-wheel enter engagement, described the first small sun gear and described the first row star-wheel keep engagement, and described cyclic train is transformed to the first positive sign mechanism; When described the second slipping mechanism is moved to the left, described the first row star-wheel and described the second planetary gear integral body move to left, described the first small sun gear and described the first row star-wheel drop out of gear are closed, described the second small sun gear and described the second planetary gear enter engagement, described the 3rd small sun gear and described the third line star-wheel keep engagement, described cyclic train is transformed to the second positive sign mechanism

Described input block comprises:

The speed of mainshaft input media being connected with described main shaft; The large sun gear rotating speed input media being connected with described gear cap,

Described data acquisition display unit comprises:

The speed of mainshaft harvester being connected with described main shaft; The planet carrier rotating speed harvester being connected with described planet carrier; The large sun gear rotating speed harvester being connected with described large sun gear; By wire, be connected with described speed of mainshaft harvester, described planet carrier rotating speed harvester, described large sun gear rotating speed harvester respectively for showing the first display, second display, the 3rd display of rotating speed.

2. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described the first slipping mechanism comprises: be connected in the first sleeve pipe on described the 3rd small sun gear; Be connected in the gear cap of described large sun gear and second sleeve pipe of empty set on described main shaft, described the second sleeve pipe is provided with groove; Be embedded in the 3rd sleeve pipe in the groove of described the second sleeve pipe, described the 3rd sleeve pipe and described the second sleeve pipe can relatively rotate, and connect the first in command of described the first sleeve pipe and described the 3rd sleeve pipe, and the described first in command has guide rail.

3. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described the second slipping mechanism comprises: be connected to the Quadruplet pipe between described the first row star-wheel and described the second planetary gear, described Quadruplet pipe is connected in described all rotating shafts, the second in command who is connected with described Quadruplet pipe.

4. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described speed of mainshaft input media is the first handwheel being connected with described main shaft, by described the first handwheel, can shake described main shaft; Described large sun gear rotating speed input media comprises: be connected in the first belt wheel on described the second sleeve pipe, be positioned at described first belt wheel the place ahead second belt wheel identical with described the first belt wheel parameter, on described the first belt wheel and described the second belt wheel, be connected with driving-belt, described the second belt wheel is connected with described the second handwheel, described the second handwheel shakes, and rotating speed can be by passing to described large sun gear by described the first belt wheel, described driving-belt, described the second belt wheel and described the second sleeve pipe successively.

5. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described speed of mainshaft input media is the stepless speed-change motor being connected with described main shaft, and described large sun gear rotating speed input media is the motor being connected on described the second sleeve pipe.

6. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described speed of mainshaft harvester is the first magnetic-type sensor being connected with described the first display by wire, and described the first magnetic-type sensor is measured the speed of mainshaft near described main shaft; Described planet carrier rotating speed harvester comprises: the second magnetic-type sensor being connected with described second display by wire, be connected in the 5th sleeve pipe on described planet carrier, described the first sleeve pipe empty set is on described the 5th sleeve pipe, and described the second magnetic-type sensor is measured planet carrier rotating speed near described the 5th sleeve pipe; Described large sun gear rotating speed harvester comprises: the 3rd magnetic-type sensor being connected with described the 3rd display by wire, described the 3rd magnetic-type sensor is measured large sun gear rotating speed near described the second sleeve pipe.

7. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described data acquisition display unit also comprises:

Be connected in the first bevel gear on described the 5th sleeve pipe; Have the second bevel gear of identical parameters with described the first bevel gear, described the first bevel gear and described the second bevel gear are in engagement; Be connected to the first bevel gear shaft between described the first bevel gear and described the second bevel gear; Be connected to the first pointer of described the first bevel gear shaft end,

Be fixed on the third hand tap gear on described main shaft; Take turns the 4th bevel gear with identical parameters with described triconodont, described third hand tap gear and described the 4th bevel gear are in engagement; Be connected to the second bevel gear shaft between described third hand tap gear and described the 4th bevel gear; Be connected to the first spur gear on described the second bevel gear shaft; Have the second spur gear of identical parameters with described the first spur gear, described the first spur gear and described the second spur gear are in engagement; Be connected to the 6th sleeve pipe on described the second spur gear, described the 6th casing pipe sleeve is on described the first bevel gear shaft; Be connected to the second pointer of described the 6th cannula end.

8. mechanical teaching aid according to claim 1, is characterized in that:

Wherein, described planet carrier is ring flange.