SU1430586A1 - Thermal engine - Google Patents

Abstract

The invention makes it possible to increase the efficiency of the engine when the loads and heating-cooling conditions change, as well as to ensure the control of the rotational speed of the power take-off link and the implementation of reversal without changing the heating-cooling conditions, as well as to increase reliability and improve the weight and size x. Rollers 4 and 5, which are rotatably mounted on base 1 on opposite sides of heater 2 and cooler 3, are connected by a mechanical transmission (MP) 7 with a power take-off link. MP 4ol is not variable with a gear ratio, and the range of the relative change in its gear ratio is twice the value of the limiting relative longitudinal thermal deformation of the working element (RE) 6 made of a material with a thermomechanical shape memory. The average value of the gear ratio MP is equal to the ratio of the radii of the rollers located on opposite sides of the heater. The rollers are provided with rims 9 of elastic material, and the OM is made in the form of a coil spring wrapped around the rims. With this design, the rollers from the side of the elongated reel act by forces that create two oppositely directed torques, which with the help of the MP are added in a ratio determined by the gear ratio of the MP. A change in the gear ratio MP changes the gear ratio of the engine and the relative elongation of the OM, which leads to a change in the speed of rotation of the power take-off shaft. 1 hp f-ly. Zil. 2 / ffi (L 4 ;: co about SP oo 05

Description

The invention relates to mechanical engineering, namely to thermal engines with weaved working elements from a material with a thermomechanical shape memory, and can be used to drive various mechanisms due to low-temperature thermal energy.

The aim of the invention is to increase the efficiency of changing loads and heating-cooling conditions, as well as providing control of the speed of rotation of the power take-off link and carrying out the reverse without changing the conditions of heating-cooling, as well as increasing reliability and improving mass-dimensional characteristics. ,

Figure 1 presents the structural scheme of the described engine - view along the axes of the rollers j in figure 2 - view A in FIG. 1 in FIG. 3 - node I in figure 1,

The engine contains a base 1 with a heater 2 and a cooler 3. Based on 1 on either side of heater 2 and cooler 3, rollers 4 and 5 are mounted for rotation, around which a flexible ring working element 6 is wrapped around a material with a thermomechanical shape memory, With rollers 4 and 5 by mechanical transmission 7, a power take-off link in the form of a shaft 8 is connected. Mechanical transmission 7 is made with a variable gear ratio, for example, as shown in FIGS. 1 and 2, in the form of a V-belt. Transmission 7 can also be made in the form of a gearbox that discretely changes the gear ratio in a given range (not shown). The range of the relative change in gear ratio 7 is equal to twice the limiting relative thermal longitudinal deformation of the working element 6, and the average value of gear ratio 7 is equal to the ratio of the radii of the rollers 4 and 5 located on opposite sides of the heater 2. The rollers 4 and 5 are fitted with rims 9 of an elastic material such as rubber, and the working element 6 is made in the form of a cylindrical coil spring (see fig.Z), wrapped around the rims 9.

The engine operates as follows.

In the heater 2, the working element 6 previously extended in the cooler 3 undergoes the reverse martensitic

transformation, restoring its original length and developing with this effort F, which is applied to rollers 4 and 5, creating the corresponding moments relative to their

axes, In cooler 3, rollers 4 and 5 stretch working element 6, and F reaction forces are applied to them, always smaller in magnitude

FU,

The forces Fj and F of the action of the working element 6 on the rollers 4 and 5 create two oppositely directed torques that are added by means of a mechanical transmission 7 in a ratio determined by the gear ratio of the transmission 7. The difference of these moments is the useful moment of the engine removed with shaft 8 PTO.

The magnitude of the reversible relative elongation l of the working element 6 in the cycle is determined by the gear ratio K. to the engine, which can be defined as the ratio of the speeds of the working element 6 at the input and output of the heater 2, t, e.

5 0 c

0

five

TO

Ab

L

U

Where

W,

W,

R, j Rj

W. iCO, to

B

f R

Bjwi. to to (1)

 R

the speed of the working element 6 at the entrance to the heater 2, M / ci the speed of the working element 6 at the exit of the heater 2, m / s the radii of the rollers 4 and 5, respectively j, the angular speed of rotation of the rollers 4 and 5, respectively

gear ratio of rollers 4 and 5i

CP

ABOUT,

W,

mechanical gear ratio 7,

Accepted in a positive direction of the rotation of the rollers clockwise, the engine torque can be calculated as follows:

F "- FO) R, MP

Mn - (FH - Ro) g.

(2)

, 31430586

le M - the moment applied by the mechanical transmission 7 to the roller 4, Nm;

M - the moment of load applied to the roller 5 and equal to the moment of the engine Nm Nm,

From (2) we get

(FH - FO) (R, K - R,) M

When R R

H

Mu

(3)

ten

h

(ТРц-Ро) / К „-1). (4) If K. 1,

"five

than those of ne and 6, which is not

WA.

Mts (FH,) (R, - R)

Moment Mde engine is equal to zero, if At the same time K p-

When Kp changes from values to values, or vice versa, the engine torque continuously changes from maximum to zero and after reverse at K (,, again to maximum. This property of the proposed engine allows, by changing the gear ratio Kp 7 of transmission, to maintain the load P „of the working element 6 is close to the maximum in all modes of operation,

The efficiency of the energy conversion process is almost directly proportional to the load FM on the working element 6 in the heating zone and reaches a maximum value with a load F approaching the yield strength of the material of the working element 6 under these conditions.

Therefore, the provision in all modes of engine operation of the load on element 6, which is close to the limiting one, makes it possible to reach the maximum average value of the PCC.

The frequency of rotation of the rollers 4 and 5 and the engine shaft 8, all other things being equal, is determined by the degree of reversible deformation of the working element 6 and the heat flow in the heating and cooling zones, Since there is a rigid connection between the relative elongation L1 of the working element 6 and the gear ratio of the engine determined by his kinematics

 1 Wi

wf A "

one.

(6)

th

ten

"five

20

25

thirty

ds -

35

40

50

55

In addition, it is known that the amount of heat required for the reverse martensitic transformation to occur, the greater the greater the relative elongation ul. Consequently, when the gear ratio Kp of the gear 7 is changed, the gear ratio Kd of the engine and the relative elongation ul of the element 6 change, which at a constant heat flux leads to a corresponding change in the speed of rotation of the power take-off shaft 8.

The use of a mechanical transmission 7 with a variable gear ratio (variator) allows the engine to adjust the torque limit on the fly, keeping the torque of the working element 6 unchanged and close to optimal tension, which ensures operation with high (same as at nominal power) efficiency with partial loads and, consequently, increases the efficiency of the engine as a whole, regardless of the heating and cooling conditions, as the load changes, adjust the frequency of rotation of the motor shaft 8, which is important when using In order to drive electric generators or vehicle propulsion devices, the OcyD ectvlyut reverse without changing the conditions for the supply and removal of heat.

The correct choice of the range of the gear ratio to the transfer 7 in accordance with the material properties of the working element 6 (i.e., equal to twice the limiting relative thermal longitudinal deformation of the material in the operating cycle) ensures the optimization of engine performance in the entire possible range of parameters in the forward and reverse direction rotation shaft 8.

Selecting the average gear ratio Kf, gear 7, equal to the ratio of the diameters of the rollers 4 and 5, which it connects, makes it possible to reverse and ensures the symmetry of the engine characteristics in the forward and reverse rotation of the shaft B.

Due to the implementation of the element 6 in the form of a coil spring, the reversible elongation of the working element 6 is increased by about 10-15 times with a corresponding decrease in the tension conditions of the element 6. This allows, with the same power and torque of the engine, to reduce the load on the supporting elements of the rollers 4 and 5 10-15 times and at the same time to ensure an increase in heat transfer surface while maintaining the compactness of the engine.

Installation on rollers 4 and 5 of the rims 9. Of the elastic material, which under the action of pressure from the turns of the working element 6 are elastically deformed, repeating the shape of the protrusions of the working element 6 and forming a similarity of protruding teeth that prevent the sliding of the working element 6 along the surface of the rollers 4 and 5, increases the reliability of starting and running the engine.

Formula invented

1, Heat engine comprising a base with a heater and a cooler mounted rotatably on a base on opposite sides of the heater and cooler

five

0

five

0

faces, wrapping around rollers a flexible ring working element from a material with a thermomechanical shape memory and a power take-off associated with mechanical transmission rollers, characterized in that, in order to increase efficiency when changing loads and heating-cooling conditions, as well as controlling the speed of rotation of the power take-off link and reversing without changing the heating-cooling conditions, the mechanical transmission is made with a variable gear ratio, and the relative range is changed and its gear ratio is twice the value of the limiting relative thermal longitudinal deformation of the working element, and the average gear ratio is equal to the ratio of the radii of the rollers, located on opposite sides of the heater, 2. The engine according to claim 1, characterized in that, in order to increase reliability and to improve the overall dimensions, the rollers are additionally equipped with rims of elastic material, and the working element is designed as a cylindrical helical spring wrapped around the bead at.

did

phase.2

FI.5

Claims (2)

Claim 1. A heat engine comprising a base with a heater and a cooler mounted on a base rotatable on either side of the heater and cooler rollers, a flexible ring working element made of material with a thermomechanical shape memory and a power take-off link connected to mechanical rollers wrapped around the rollers transmission, characterized in that, in order to increase efficiency when changing loads and heating and cooling conditions, as well as to provide regulation of the link rotation speed • power take-off and the phenomenon of reversal * without changes in the conditions of heating and cooling, the mechanical transmission is made with a variable gear ratio, and the range of relative changes in its gear ratio is equal to twice the limiting relative thermal longitudinal deformation of the working element, and the average gear ratio is equal to the ratio of the radii of the rollers located at different sides of the heater. 2. The engine according to claim 1, characterized in that, in order to increase reliability and improve weight and size characteristics, the rollers are additionally equipped with rims of elastic material, and the working element is made in the form of a cylindrical coil spring wrapped around rims. fae. 2 fie. 5